Use of Sftp in SQL Server Merge Replication

I am using SQL merge replication to synchronize data between offline client database and central database server. On client machine MSDE and on server MS SQL Server 2000 is being used. Data transfer is bi-directional. Replication is done over the ftp. As ftp is non-secured, synchronization is being done over VPN connection. Synchronization is initiated through .net application.

As per new requirement, SQL merge replication needs to be done over secured channel without using VPN. Could you let me know a) what are the secured protocols supported by SQL Merge Replication? b) What are the various options available to perform SQL Merge replication over secured channel (sftp,SSL etc) ?

The SSL encryption is performed within the Super Socket Net-Library (Dbnetlib.dll and Ssnetlib.dll) and applies to all inter-computer protocols supported by SQL Server 2000. And also you can use Multi-protocol with encryption facility, for more information review books online.